Linguists are generally frustrated when they read the work of colleagues from other disciplines (geography, agronomy, soil science, botany, zoology, entomology). Technical terms are not always found there in the language of the region being studied, or if they can be found, they are not always easily recognizable due to a lack of standardized spelling. These specialists, in turn, do not bother to go and see the work of their linguist colleagues who, they think, and they are not necessarily wrong, will hardly provide them with information on the subjects that interest them. In order to establish a bridge between Fulfulde speakers and specialists in disciplines related to the natural environment and "development" – agricultural, pastoral, fisheries, medical, etc. –, I undertook, in the 1990s, to produce a dictionary that compares the knowledge conveyed by the Fulani language (or Fulfulde) with the knowledge generated by research carried out in European languages. The working method had to combine a bibliographic approach and field research, mainly in the form of interviews in the Fulani language.